The present invention relates to a running operation history collecting method and device in NC machining which can extract all kinds of running operation performed during NC machining and machining conditions which are modified resulting from the running operation and can store the running operation and machining conditions as information which will be available in an expansive manner to the numerically controlled machine tool operated or other numerically controlled machine tools.
Operation of numerically controlled machine tools can be automatically controlled by inputting NC programs, and lately such machine tools are widely used in various industrial fields as computerized numerically controlled machine tools (CNC machine tools) in combination with micro processing technology, power electronics technology, or software technology.
Generally, numerical control information, such as an NC program, is composed of a tool exchange command, a spindle speed command, a cutting speed command, a feed rate command, a spindle movement/interpolation command, miscellaneous function command, or the like, and numerical control information suitable for such a machine tool which is an object of machining control is prepared as an NC program as occasion demands.
By adding material data and shapes of final components, the conventional numerical control information is prepared as a desired NC program using a CAD-CAM system, an automatic programming tool, or the like and then a simulation or test cutting is repeated using an actual machine tool and at the same time an adjustment (editing for correction) of the NC program is made on site, whereby the information is finally used for machining control of machine tools as an NC program for actual machining. Such a generating process for a conventional NC program will be described with reference to FIG. 1. A process design section 1 is provided with material data composed of a workpiece shape, drawing data or the like and shapes of final components, and each process is determined based on information relating to machine tools, jigs, and holders which is read out from a machine specification data base 2 and a jig/holder database 3. Here, a process means a series of machining operations to be carried out using a machine tool without changing a fixed posture of the workpiece. Further, a machining element means a group of a plurality of work elements in an identical machining position of the workpiece. In other words, a work element means single machining carried out by each tool, for example, a single operation, such as drilling or facing. Further, a machining element means that single machining is completed by combining a plurality of work elements in an identical machining position of the work. For example, in the case of tapped hole machining, a machining element is composed of three work elements, such as center hole machining, lower hole machining, and tap machining.
First, the process design section 1 determines such a process, and then in a work design section 4, a machining element to be machined at each process and a work element required for completing the machining element is recognized based on a work development database 5, and numerical control information, which is provided by an expression such as xe2x80x9ca first process NC program 9, a second process NC program 10, ...xe2x80x9d using each item of information relating to machining from a tool data base 6, a cutting condition data base 7, and a machining time computation data base 8, is outputted. There is a problem that the NC program made in such a manner cannot be an optimum NC program. Thus, the NC program mentioned above is sent to an NC program correction editing section 11, and then a machining operator performs modification and editing of the NC program so as to optimize a tool path and cutting conditions, such as a cutting speed, a feed rate, and a cutting depth, while carrying out a simulation, no-load running, or test cutting. The optimized NC program is inputted to a numerical control section 14 as xe2x80x9ca post-modification first process NC program 12, a post-modification second process NC program 13 . . .xe2x80x9d and it is used for actual machining. For such optimization, in addition to the execution of simulation or test cutting described above, it is necessary to incorporate know-how in field work. Such modification work is only put into practice as occasion demands, and it is not systematically input as machining technology or know-how acquired by machining operators and is not maintained in an easily usable form.
For example, if abnormal oscillation or noise arises while carrying out test cutting using an NC program outputted from a CAM system, a machining operator is supposed to immediately judge what the cause is and take measures based on machining technology and know-how in machining obtained by his or her own experience or study. More specifically, if there is problem with a spindle speed, the spindle speed will be regulated to an appropriate value by manipulating a spindle speed override switch on an NC console panel. If there is a problem with a feed rate, the feed rate will be regulated to an appropriate value by manipulating a feed rate override switch on the NC console panel. Also, if there is a problem with a cutting depth, while operating the NC program, a pulse handle superimposition mode will be set and the cutting depth will be regulated to an appropriate depth using a pulse handle. Further, if chips are not appropriately removed and become entangled in an edge of a tool, manual operation will be interrupted during drilling performed according to the NC program and a drill will be pulled out from a hole using a manual feed button. Also, after removing the chips entangled in the edge, a manual operation mode will be released and drilling will be commenced again. In any case, the machining operator performs modification and editing of the NC program based on the results of intervention operations at the time of test cutting. However, the various intervention operations performed by the machining operator at the time of test cutting resulted in successful adjustment, but it served as an optimum machining command on the NC program only on such particular occasions. The operator failed to leave concrete information as to how and why adjustments were made to machining s machining know-how.
Further, PCT/JP96/03264 the title of which is xe2x80x9cNC program analyzing method and device in NC machiningxe2x80x9d discloses a method and device which analyze an NC program already modified and edited as described above and used for actual machining, extracts know-how in field work or other various machining conditions, namely, optimum information for machining or optimum cutting conditions for particular work, and uses them as a data base. However, in this device and method, a machining method analyzing section 15 fetches information regarding machining or machining conditions which are stored on the NC program already modified and edited by the machining operator as shown in FIG. 2, and a data base preparation section 16 prepares them as a data base. Therefore, it is impossible to fetch only the adjustment operation for every kind performed by the machining operator at the time of test cutting as know-how in machining.
As described above, the problem of conventional NC machining systems is that in the test cutting and the modification and editing work using the NC program which are performed by a machining operator as a routine work, it was difficult to systematically put in order and preserve in an available form the variable machining technology and know-how in machining which can be obtained only through the operator""s work as described above. This means that heretofore a system administrator and a system operator did not have means to know what kind of know-how in machining the machining operator uses on site as well as means to feed back the know-how in machining acquired by the machining operator into the system. As a result, it causes a vicious circle where the machining operator repeats the daily adjustment work described above.
The present invention is made in consideration of the conventional problems described above. An object of the present invention is to make it possible to extract various running operations for adjustment and modification carried out on site in order for an NC program operation performed by a machining operator to be suitable for machining circumstances and/or to extract machining conditions modified resulting from the running operation and to use the one extracted as a data base. The running operation and the machining conditions modified which are extracted in such a manner can be fed back into a CAD-CAM system or an automatic programming system as a data base in which know-how in machining on site is accumulated. Further, by producing a data base in such a manner, the know-how in machining acquired by a particular machining operator is not limited to an individual, but available to everyone in the entire factory.
The present invention has running operation extracting means or a running operation extracting step which extracts running operations performed at the time of a machining operation using an NC program and/or a machining condition modified resulting from the running operation and running operation storing means or a running operation storing step which stores in a rewritable manner the running operation and/or the modified machining condition, either or both of which are extracted.
Further, the running operation extracting means include means for extracting, every time a work element is machined, the running operation and/or the machining conditions modified resulting from the running operation.
Further, the running operation extracting means include means for extracting modifying operations for a feed rate, a spindle speed, or a cutting depth.
Further, the present invention includes a medium in which a program is recorded for executing a running operation extracting procedure for extracting a running operation performed at the time of a machining operation using an NC program and/or a machining condition modified resulting from the running operation and for executing a running operation storing procedure for storing in a rewritable manner the running operation and/or the modified machining condition, either or both of which are extracted.